Mesoporous MnO2 as enzyme immobilization host for amperometric glucose biosensor construction

Mesoporous MnO2 (mesoMnO2) is synthesized facilely through sol–gel process using nonionic surfactant polyxyethylene fatty alcohol (AEO9) as template. Transmission electron microscopy (TEM) image and N2 adsorption/desorption isotherm show that the obtained mesoMnO2 material presents disordered porous structure and appropriate pore size suitable for the immobilization of glucose oxidase (GOx). An amperometric glucose biosensor based on GOx entrapped in mesoMnO2 is fabricated, in which mesoMnO2 also acts as a catalyst for the electrochemical oxidation of H2O2 produced by enzyme reaction. The biosensor shows fast and sensitive current response to glucose in the linear range of 0.0009–2.73 mM. The response time (t95%) is less than 7 s. The sensitivity and detection limit are 24.2 μA cm−2 mM−1 and 1.8 × 10−7 M (S/N = 3), respectively. This indicates that mesoMnO2 has promising application in enzyme immobilization and biosensor construction.